Cpu fans runs high nothing on any monitor(s)

[nickshondacbr600]

a friend and i both have an HP i bought mine back in 06 and he got his 2-3 months later, a1603n model.
i would shut the comuter down and when starting it up the next day sometimes it would come on and other it wouldn't, 2-3 tries to get it to boot, now it just runs the CPU fan at a very high speed but the monitor stays black, have tried 2 other monitors that work on other PCs and they work fine. now 3 months later after my problem my friend that has the same problem we cleaned the CPU fan and unit then it wouldn't start up same exact thing that happend to mine. i've been told the mother board is going or gone. seems to make sense but both comps were running fine and then poof dead MB's?? on both same age and everything.

 

[jsc]

This is oriented toward a new build that won't boot, but anyone can use the checklist and troubleshooting ideas.

New computer won't POST
http://www.tomshardware.co.uk/forum/page-261145_13_0.html

SInce you and your friend have the same or similar models, you should be able to work together.

I find it unlikely that two similar three year old computers have motherboards that died at the same time.